On Mon, Nov 21, 2011 at 6:43 PM, Robert Haas <robertmh...@gmail.com> wrote: > In buffer fill mode, we scan the index and add matching tuples and > their CTIDs to the buffer. When the buffer is full or the index AM > reports that there are no more tuples in the scan, we switch to buffer > drain mode.
Instead you could do the two phases concurrently the way tuplesort implements the tapesort from Knuth. You keep a heap of ctids with an epoch. You fill the heap then you return the first one. Whenever you return one you read the next one and add it to the heap. If it falls before the last returned value you insert it with the next epoch but if it falls afterwards you can insert it into the heap in its correct position. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
